I am currently using the R package "rgrass7" (Version: 0.1-6) in order to
command GRASS GIS (Windows7, OSGEO4W installation).
I use R in order to start a GRASS environment and to script my geoprocessing.
Both is working fine. However, I have problems with storing and calling the
GRASS gisenv variables.
Every time when I call "initGRASS" a file called "junk" is created containing
GRASS gisenv variables.
Looking at the source of the initGRASS function the section below puzzeled me
somehow:
59 Sys.setenv(GISRC = paste(Sys.getenv("HOME"), "\\.grassrc7",
60 sep = ""))
61 if (file.exists(Sys.getenv("GISRC")) && !override)
62 stop("A GISRC file already exists; to override, set override=TRUE")
63 Sys.setenv(GISRC = "junk")
64 cat("GISDBASE:", getwd(), "\n", file = Sys.getenv("GISRC"))
65 cat("LOCATION_NAME: <UNKNOWN>", "\n", file = Sys.getenv("GISRC"),
66 append = TRUE)
67 cat("MAPSET: <UNKNOWN>", "\n", file = Sys.getenv("GISRC"),
68 append = TRUE)
69 gisrc <- ifelse(use_g.dirseps.exe, system(paste("g.dirseps.exe -g",
70 shQuote(Sys.getenv("GISRC"))), intern = TRUE), Sys.getenv("GISRC"))
71 assign("addEXE", .addexe(), envir = .GRASS_CACHE)
72 Sys.setenv(GISRC = gisrc)
First, why is initGRASS using ".grassrc7" for storing the GISRC file?
InitGRASS is looking for the GISRC file under ".grassrc7" (line 59). However,
in the package documentation [1], the GISRC file is called ".gisrc". Moreover,
the GRASS documentation says that the GISRC file is stored under "/.grass7/rc"
Second, what is the purpose of assigning "junk" to the GISRC environment
variable?
GISRC is set to "junk" (line 63) and then the GISRC value ("junk") is assigned
again back to system variable GISRC. Unless I misinterpreded the code, it does
not make much sense to me. Shouldn't the enviroment varibales not be written
(line 64 - 68) to ".grassrc7" rather than to "junk"?
I would appreciate any support or hints!
Regards,
Roger
[1] http://https//cran.r-project.org/web/packages/rgrass7/rgrass7.pdf
[2] http://grass.osgeo.org/grass70/manuals/variables.html
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